Cleaning nets like "leaf rakes," herein defined as nets whose depth of collecting pouch is about equal to or about twice as great as the smallest dimension of the opening into the net, and "skimmers," which are similar but have a shallower net, have been in use for many years. Although they may vary somewhat in size and shape, leaf rakes and skimmers have common structural features. One feature is that netting material is usually attached to the frame by wrapping it around the frame and applying a conformal metal or plastic cover sheath which secures the net to the frame and protects it from abrasion during use. Since netting material has a relatively short life, due to mechanical wear and the action of sunlight and water chemicals, it requires frequent replacement. As existing nets are designed, netting replacement by the end user is usually difficult because the netting must be held in a precise relationship to the frame with one hand while the cover sheath is attached with the other. Often, special tools are required, or the entire net must be replaced or returned to the manufacturer for repair. This net replacement problem has been addressed specifically in U.S. Pat. No. 4,169,331 which describes a net which is relatively easy to replace. However, fastening the net to the frame by means of a very special plastic frame cover to which the net is secured by a molding process is inherently expensive. The net fastening method described in U.S. Pat. No. 3,220,037 is a simpler, less expensive solution but requires considerable skill and/or special tools to accomplish the task. Another feature is that the rigid, net-supporting frame is permanently assembled to the short handle that is used for quick connect-disconnect attachment of the net to a long extension pole. If the frame is accidently bent or otherwise damaged, for example, in many cases the entire assembly including the frame and its short attachment handle must be replaced. An attempt to alleviate the handle problem is presented in U.S. Pat. No. 2,706,664 wherein a simple method of assembling a frame with round cross-section is shown. However, it is not easily adaptable to frames of rectangular or girder shaped cross-section. The assembly method shown for a frame of rectangular cross-section in U.S. Pat. No. 3,220,037 not only requires special tooling for assembly but also results in a high stress point at the sharp corners where the frame enters the handle.
In addition to the problems of netting and parts replacement resulting from the design features of existing nets, there are operational difficulties arising from features omitted from their design. One deficiency of existing leaf rakes is that there is no provision to keep leaves and debris from coming back out of the net as it is pushed along, resulting in lost time for pool servicemen. U.S. Pat. No. 4,003,100 describes a net structure intended to retain collected debris during use. The form of this net with its rigid entry member and nominally vertical orientation of net opening does not lend itself well to most pool cleaning applications because the form of underwater pool surfaces requires some flexibility and curvature of the net entrance lip. Another common deficiency is that the edge of the net where it contacts the pool surfaces is generally round or blunt, thus making it difficult to coax leaves very close to the bottom of the pool into the net. An example of a special edge structure which has a lip designed to capture debris adhering to pool wall surfaces is given in U.S. Pat. No. 3,220,037. The difficulty with this device is that the net must be inverted in order for the lip to work effectively. Another design feature common to most existing nets is that they are manufactured as permanent assemblies which cannot easily be disassembled or assembled in the field. Therefore, they must be shipped and stored in larger, space consuming containers than would be required if they could be broken down into a more compact package.